Reliability & Resilience
Design as though everything will eventually fail, because it will.
20 topics in this area.
Each topic is the unit content is filed against. Topics with nothing in them yet are shown too — they are the honest edge of the curriculum rather than a gap being hidden.
Reliability & Resilience
General material on designing for failure.
SLI, SLO & SLA
The measurement, the internal target, and the contractual commitment.
Error Budgets
Unreliability as a resource that feature velocity spends.
Availability Mathematics
Series dependencies multiplying, and redundancy that is not independent.
RTO & RPO
How long recovery may take and how much data may be lost.
Redundancy
N+1, N+2 and 2N, correlated failure, and headroom for the failure itself.
Failover
Detection latency, promotion, fencing and the cost of failing over wrongly.
Graceful Degradation
Reduced but useful function when a dependency is gone.
Fault Isolation
Cells, zones, tenants and the partitions that bound a failure.
Chaos Engineering
Hypothesis-driven failure injection with a bounded blast radius.
Game Days
Testing the response — runbooks, access, comms — not only the system.
Incident Management
Command roles, severity levels and mitigation before diagnosis.
Postmortems
Finding the systemic conditions, and completing the actions afterwards.
On-Call
Sustainable rotations, actionable pages and handover discipline.
Capacity Planning
What does not autoscale, and the lead-time items that need a date.
DR Testing
Restore drills, timed against the stated RTO, into a clean environment.
Resilience Testing
Exercising retries, breakers and fallbacks that are otherwise never run.
Static Stability
Serving from existing state when the control plane is unavailable.
Degradation Modes
Deciding in advance what is shed first and what is protected.
Reliability Culture
Blamelessness, error budget policy and reliability as a funded property.